Side bearing for railroad cars

ABSTRACT

A preloadable side bearing for railroad cars having a mass of hard elastomeric material on a base adapted for attachment to a supporting surface, such as the truck bolster of a railroad car with provision for an initial reduction in the overall height of the bearing in response to preloading forces and to then absorb substantial loading forces with resulting compressive depression of the mass and wherein the mass is formed of a material such as polyurethane.

United States Patent John H. van Moss. Jr.

[72] inventor Highland, Ill.

[21 Appl. No. 767,450

[22] Filed Oct. 14, 1968 {45] Patented Jan. 19, 1971 [73] AssigneeVanguard Corporation a corporation of Illinois [54] SIDE BEARING FORRAILROAD CARS 8 Claims, 8 Drawing Figs.

[52] US. Cl 267/3, 267/1 F161 1/36 267/3. 6,

[56] References Cited UNITED STATES PATENTS 3,035,825 5/1962 Weller267/1(52) 3,045.998 7/1962 Hirst 267/3 Primary Examiner--James B.Marbert Attorney-Rummler & Snow ABSTRACT: A preloadable side bearing forrailroad cars having a mass of hard elastomeric material on a baseadapted for attachment to a supporting surface, such as the truckbolster of a railroad car with provision for an initial reduction in theoverall height of the bearing in response to preloading forces and tothen absorb substantial loading forces with resulting compressivedepression of the mass and wherein the mass is formed of a material suchas polyurethane.

SIDE BEARING FOR RAILROAD CARS BACKGROUND OF THE INVENTION Thisinvention relates to a preloadable side bearing for use with railroadcars and for positioning between the car body and a truck bolster to becompressed under preloading forces and receive forces encountered as thecar body swings to reduce harmonic rocking of the car body andresultingly reduce the frequency of derailments.

Side bearings have been known for many years embodying rollers movablymounted in a frame supported on a truck bolster which could be contactedby the car body. Also, preloaded side bearings are known utilizingspring-loaded cam systems resulting in a complicated construction.Insofar as solving the problem of harmonic rocking motion resultinginderailments, it has been known to utilize snubber members used inconjunction with the spring groups between the truck bolster and theside frame of the truck. None of the foregoing, as well as othervariations thereof, have been found to provide an inexpensive structurewhich will reduce the harmonic condition which causes the car bodies tosway from side to side and created a problem which is known in therailroad industry as rock and roll." More specifically, this conditionhas been encountered with high covered hopper cars and some high sidegondolas capable of carrying between 100 and 125 tons of material. Thesecars'are normally approximately the same length as the standard rail andwith the staggered joints between the rails, the harmonic condition wasset up at some of the lower speeds of travel. I 1

As now understood. this swinging of the car body from one side to theother contacted against the side bearing which is located between thecar body and the truck bolster. The forces were transmitted through thebolster and into the spring group and the side frame of the truck. Fromthere, the force went through the car journals and onto the axles on theoutboard side of the wheels of the truck. This caused the wheels and therail on that particular side to form a fulcrum point and the axles andwheels rotated about that fulcrumpoint, lifting the wheel from the trackon the opposite side. This has not been a new condition. However in thepast, most of the time the wheels on the far side returned and madecontact with the rail. In these newer cars with larger loads and greaterfrequency of the harmonic condition, the wheels were returning to thelevel and missing the rail, causing derailments. A second conditionwhich is causing derailments is believed to be where the harmonicrocking of the car body becomes so violent that the loads transmitteddown through the truck bolsters and frame into the wheels are greatenough to actually turn the rail over.

At the present time, there are no firm specifications by the Associationby American Railroads regarding resilient-type side bearings; however,it has been decided informally that such side bearings should have aninitial preload of 5,000 lbs. on each side of the car, with a deflectionof the resilient side bearing of approximately /4 inch and as the carbody rocks the resistance of the side bearing should increase to 50,000lbs. with an additional deflection of approximately linch. The sidebearing disclosed herein substantially meets the foregoing in-.

SUMMARY An object of this invention is to provide a new and improvedpreloadable side bearing for use with railroad cars which reduces thelikelihood of derailment in a railroad car.

Another object of the invention is to provide a preloadable side bearingfor positioning between the frame of a railroad car and the truckbolster comprising a base member attachable to the truck bolster, asymmetrically shaped mass of hard elastomeric material extendingupwardly from the base with the periphery thereof being shaped to permitoutward movement of the material without significantly increasing theoverall dimension of the mass of material.

Still another object of the invention is to provide a preloadable sidebearing as defined in the preceding paragraph wherein the upper andlower ends of the mass of elastomeric material are outwardly concave topermit initial compression of the bearing with an initial preloadingforce without requiring sultstantial compression of the entire massofmaterial.

Still another object of the invention is to provide a preloadable sidebearing, wherein the base member and shaped mass of elastomeric materialare formed integrally of the same material.

An additional object of the invention is to provide a preloadable'sidebearing. as defined in the preceding paragraph and a combination thereofwith a railroad car, wherein said elastomeric material has a hardness ofapproximately 50Shore D Scale or harder and provides an initialdeflection of the side bearing of approximately V4 inch under 5,000 lbs.loading and limits additional deflection to approximately l inch underadditional loading of approximately 50,000 lbs.

A further object is to have a wear member in the form of a cap alsoformed of the elastomeric material and fitted over the mass and withparticles of material. such as Teflon, embedded therein to provide aslippery surface for the wear member.

Further objects and advantages will become apparent from the followingdetailed description taken in connection with the accompanying drawings.

DESCRIPTION OF THE DRAWING the side bearing;

FIG. 6 is a central vertical section of a fourth embodiment of the sidebearing; 4

FIG. 7 is a partial central vertical section of a modification of thefourth embodiment; and

FIG. 8 is a central vertical section of a preferred embodiment of theside bearing.

DESCRIPTION OF THE EMBODIMENTS While this invention is susceptible ofembodiment in many different forms, there is showing in the drawings andwill be described herein in detail a preferred embodiment of theinvention together with modifications thereof with the understandingthat the present disclosure is to be considered as an exemplification ofthe principles of the invention and is not intended to limit theinvention to the embodiments illustrated. The scope of the inventionwill be pointed out in the appended claims.

In order to illustrate the utilization of the side bearing and thecombination, the associated components of a railroad car are showingtherewith in FIG. I, wherein a truck bolster I0 underlies the car frame11 of the car body and with the preloaded side bearing indicatedgenerally at 12 disposed therebetween and attached to the truck bolster10 bybolts 14 and with the upper surface thereof in engagement with aplate 15 secured to the underside of the car frame 11. When the carframe is assembled to the truck bolster, the parts are interfitted withthe frame resting on the center plate of the truck bolster and with theheight of the side bearing 12 designed to provide for an initialdeflection under a predetermined loading. As mentioned previously, theinformal specifications, at this time, specify that an initial contactload of 5,000 lbs. will result in a deflection of the side bearing ofapproximately /4 inch.

The first embodiment of the side bearing 12 is shown in FIGS. 2 and 3and includes parts formed as weldments, including base member 20 havinga series of openings 21, 22, and 23 extendingth'e'r'ethrough, with theopenings 21 and 23 providing for'pa'ssag of attachment bolts 14therethrough and with the opening 22permitting access for welding a weld24 to the underside of a spacer plate 26 resting upon the upper face ofthe base memberi20. Anannular member 27 surrounds the spacer member 26and is welded to the base member as indicated at 28 and has an 'annularupstanding flange extending upwardly beyond the spacer member. Theannular member and spacer 26 together define a well for receiving asymmetrical mass 30 of hard elastomeric material forming the resilientcomponent of the side bearing. This mass has a somewhat cylindricalshape, but is especially contoured to provide a polyrate polynomialspring which is a solid, .nonlinear spring having the desired springrate and resulting in a force-displacement curve defined by apolynomial. The shape of the spring can be described by a polynomial ofrevolution. The mass 30 has a side surface with an upper perimetral part31 and a lower perimetral part 32 and with an outwardly concave section33 thcrebetween. The lower perimetral part 32 fits within the welldefined by the annular member 27 and spacer 26 and with the peripherythereof engaging against the inner side of the annular flange 27.

A wear member is positioned on the top surface of the mass 30 and, asshown in FIGS. 2 and 3, embodies an inverted cup 35 having a dependingperipheral flange 36 which surrounds and fits against the upperperimetral part 31 of the mass. In the embodiment of FIGS. 2 and 3, allof the parts, except for the mass 30, are formed of suitable metalstructure to provide the desired strength and wear characteristics.

The outwardly concave section 33 of the elastomeric mass 30 contributesto the desired compression under loading of the side bearing and alsofunctions to avoid bulging of the mass 30 outwardly beyond the diameterof the perimetral parts 31 and 32 under expected loads. Also,substantial radial loading on the perimetral parts 31 and 32 is avoidedto avoid substantial outward forces on the flanges 27 and 36 and deformation thereof which might otherwise result.

A suitable elastomeric material for the mass 30 has been found to bepolyurethane material and, in order for this material to handle theloads that can be expected in service, testing has shown that thematerial should have a hardness of approximately 50 Shore D Scale orharder. It has been found that these loads can approach 200,000 lbs.just prior to derailment of a railroad car. One example of such materialis Thiokols Solithane L-650.

In order to provide the initial depression of the bearing under thepreloading condition, the top 40 and bottom 41 of the mass 30 are eachoutwardly concave to provide a limited amount of material in theperimetral parts 31 and 32 which offers a relatively minor degree ofresistance to the initial preloading force in order to obtain thedesired overall reduction in height of the side bearing.

The second embodiment shown in FIG. 4 is generally similar to that shownin FIGS. 2 and 3 and similar parts have been given the same referencenumeral with 200 added thereto.

In this embodiment, the lower mounting member for the mass 230 is formedas a hot-pressed cup 250 which is welded to the base member 220, asindicated at 251, and which has a spacer plate 252 fitted therein andwelded thereto by a weld 253.

The upper wear member is provided by a cap 260 which is the same unit asthe cup 250 and which is inverted and fitted over the upper perimetralpart 231 of the mass 230 and with a spacer plate 261 fitted therein andwelded to the wear member as indicated at 262.

A third embodiment of the invention is shown in FIG. and the samereference numerals are used as in the embodiment of FIG. 3, with 300added thereto.

In this embodiment, a forged cup,3.60 is welded to the base member 320,as indicated at 361, aiidh'as the upstanding annular flange 362 whichreceives the spring mass 330 with an identical cup inverted to form acap we ar,mem ber 365 with a depending annular flange 366 surroundingthe upper perimetral part 331 of'the mass 330, The action of this sidebearing will be the same as that described 'with'respect to theembodiment of FIGS. 2 and 3.

A further embodiment is shown in FlG'.-.6 wherein the base member 400and mass 401 defining the spring section of the side bearing are formedintegrally of the sarnematerial us the mass 30 of the embodiment ofFIGS. 2 and-3:;and wherein openings 402 and 403 in the base member areprovided with metal sleeves 404 and 405, respectively, through whichattaching bolts 14 can extend and which can be tightened against theupper ends of the sleeves. The spring section 401 has the upperperimetral part 410 and a lower perimetral part which is not exposedbecause of the integral nature thereof with the base member 400, but ineffect is at the location of the joint 411 between the section 401 andthe base 400. Similarly, the side surface is outwardly concave. as shownat 412, and the top and bottom are outwardly concave. as indicated at415 and 416.

In the embodiment of FIG. 6, the wear member cap 420 is formed of thesame material as the base 400 and spring section 401 and with theaddition thereto, in the formulation, of particles of either Teflon onmolydisulfide to make the upper surface thereof slippery to facilitate,relative movement between such surfaces and the plate 15 depending fromthe car frame 11.

The embodiment of FIG. 6 provides all of the new results described inconnection with the preceding embodiments with the added featuresofrequiring minimal manufacturing steps with the spring section .401 andbase=400 being formed as an integral casting of the elastomericmaterial.

Optionally, a steel ring 425 can be bonded to the interior of the cap420 as a strengthening rib or retainer to add strength of the cap asshown in the embodiment of FIG. 7.

The preferred embodiment is shown in FIG. 8 and incor' porates anintegral base and spring section of the hard, elastomeric materialsimilarly to the embodiments of FIGS. 6 and 7. In the embodiment of FIG8, the base section 500 has a pair of openings, one of which is shown at501, and which receives a sleeve 502 for attachment to the truckbolster. The spring section 505 is symmetrical and extends upwardly fromthe base 500 and has a frustoconical shape. This shape provides maximumstrength for the side bearing in the area where the spring section 505joins the base 500 to prevent rollover of the side bearing in use.

In the embodiment of FIG. 8, the initial deflection under preloading isprovided by the contouring of the upper surface 508 of the springsection 505, with the central part thereof being flat and with an outerperimetrical part 509 sloping downwardly to the outer perimeter 510 ofthe spring section. This shaping of the upper surface of the sidebearing permits a limited amount of the elastomeric material to compressunder the initial deflection forces.

The upper portion of the spring section can have suitable materialembedded therein to provide a slippery surface, similarly to the cap 420of the embodiment of FIG. 6.

The frustoconical shape of the spring section 505 permits outwardexpansion of the spring section under substantial loading forces withoutsubstantial increase in the maximum diameter of the spring section.

In order to reduce the amount of elastomeric material used in formingthe side bearing, a low-cost plug 515 of metal or other material can bepositioned in a recess formed in the base 500 and extending into theinterior of the spring section 505. The exact dimensions of this plugcan be designed to limit the maximum deflection of the side bearingunder maximum loading conditions by causing the railroad car frame, ineffect, to bottom on the plug. This plug would also function as a safetystop to limit tilting of the railroad car frame.

Iclaim:

l. A preloadable side bearing forpositioning between the frame of arailroad car and the truck bolster comprising, a base member attachableto the truck bolster. a shaped mass of hard elastomeric material of ahardness of at least 50 Shore D Scale, extending upwardly from said basewith the periphery thereof being predominantly outwardly concave and theends of said mass are outwardly concave to subject a limited portion ofsaid mass to initial preloading forces, said base extending outwardlyfrom said shaped mass atthe lower end thereof, and a wear cap on theupper end of said mass.

2. A preloadable side bearing as defined in claim 1 wherein saidelastomeric material is a polyurethane material.

3. A preloadable side bearing as definedin claim I wherein said cap isformed of the same material as said mass with particles of anothermaterial such as Teflon embedded therein to provide a slippery surfacefor the wear cap.

4. A preloadable side bearing as defined in claim 1 wherein said base isthe the same material assai'd mass and is integral therewith.

5. A preloadable side bearing for positioning between the frame of arailroad car and the truck bolster comprising, a base member with anupstanding annular flange extending upwardly therefrom, a spring membercomprising a shaped onepiece mass of hard elastomeric material of ahardness of approximately 50 Shore D Scale or harder and having a saidsurface with upper and lower perimetral parts and the lower part fittedwithin said flange, said side surface being outwardly concave betweensaid upper and lower perimetral parts to permit substantial outwardmovement of said sidewall between said perimetral parts as caused bycompressive depression of said mass with the side wall remaining withinthe peripheral dimension established by said upper and lowerperimetralparts and without substantial radial loading of said flange. the top andbottom of said mass being outwardly concave to provide a limited amountof material in said perimetral parts to permit initial depressivemovement of said bearing with an initial preload force, and a wearmember in the form of a cap on the top of said mass having a dependingflange positioned around said upper perimetral part,

6. In combination with arailroad car having a body and a truck bolster,a side bearing having a base attached to said truck bolster, afrustoconical-shaped integral mass of elastomeric material having ahardness of at least approximately 50 to Shore D Scale integral with andextending upwardly from said base, said base formed integrally at thelower end of said integral mass and having lateral projections extendingoutwardly of said integral mass for attachment to the truck bolster, andthe top of said mass having a shape to cause only a part thereto to besubjected to preloading forces.

7. A side bearing as defined in claim 6 wherein the upper end of saidspring section is shaped to permit initial deflection of only the shapedportion of the side bearing upper end under preloading forces.

8. A side bearing as defined in claim 7 wherein a plug member is fittedwithin the base and spring section to reduce the required amount ofelastomer and provide a safety stop for the side bearing.

1. A preloadable side bearing for positioning between the frame of arailroad car and the truck bolster comprising, a base member attachableto the truck bolster, a shaped mass of hard elastomeric material of ahardness of at least 50 Shore D Scale, extending upwardly from said basewith the periphery thereof being predominantly outwardly concave and theends of said mass are outwardly concave to subject a limited portion ofsaid mass to initial preloading forces, said base extending outwardlyfrom said shaped mass at the lower end thereof, and a wear cap on theupper end of said mass.
 2. A preloadable side bearing as defined inclaim 1 wherein said elastomeric material is a polyurethane material. 3.A preloadable side bearing as defined in claim 1 wherein said cap isformed of the same material as said mass with particles of anothermaterial such as Teflon embedded therein to provide a slippery surfacefor the wear cap.
 4. A preloadable side bearing as defined in claim 1wherein said base is the the same material as said mass and is integraltherewith.
 5. A preloadable side bearing for positioning between theframe of a railroad car and the truck bolster comprising, a base memberwith an upstanding annular flange extending upwardly therefrom, a springmember comprising a shaped one-piece mass of hard elastomeric materialof a hardness of approximately 50 Shore D Scale or harder and having asaid surface with upper and lower perimetral parts and the lower partfitted within said flange, said side surface being outwardly concavebetween said upper and lower perimetral parts to permit substantialoutward movement of said sidewall between said perimetral parts ascaused by compressive depression of said mass with the side wallremaining within the peripheral dimension established by said upper andlower perimetral parts and without substantial radial loading of saidflange, the top and bottom of said mass being outwardly concave toprovide a limited amount of material in said perimetral parts to permitinitial depressive movement of said bearing with an initial preloadforce, and a wear member in the form of a cap on the top of said masshaving a depending flange positioned around said upper perimetral part.6. In combination with a railroad car having a body and a truck bolster,a side bearing having a base attached to said truck bolster, afrustoconical-shaped integral mass of elastomeric material having ahardness of at least approximately 50 to 90 Shore D Scale integral withand extending upwardly from said base, said base formed integrally atthe lower end of said integral mass and having lateral projectionsextending outwardly of said integral mass for attachment to the truckbolster, and the top of said mass having a shape to cause only a partthereto to be subjected to preloading forces.
 7. A side bearing asdefined in claim 6 wherein the upper end of said spring section isshaped to permit initial deflection of only the shaped Portion of theside bearing upper end under preloading forces.
 8. A side bearing asdefined in claim 7 wherein a plug member is fitted within the base andspring section to reduce the required amount of elastomer and provide asafety stop for the side bearing.